title: Concentrations and speciation of heavy metals in sludge from nine textile dyeing plants.
abstract: The safe disposal of sludge from textile dyeing industry requires research on bioavailability and concentration of heavy metals. In this study, concentrations and chemical speciation of heavy metals (Cd, Cr, Cu, Ni, Zn, Pb) in sludge from nine different textile dyeing plants were examined. Some physiochemical features of sludge from textile dyeing industry were determined, and a sequential extraction procedure recommended by the Community Bureau of Reference (BCR) was used to study the metal speciation. Cluster analysis (CA) and principal component analysis (PCA) were applied to provide additional information regarding differences in sludge composition. The results showed that Zn and Cu contents were the highest, followed by Ni, Cr, Cd and Pb. The concentration of Cd and Ni in some sludge samples exceeded the standard suggested for acidic soils in China (GB18918-2002). In sludge from textile dyeing plants, Pb, Cd and Cr were principally distributed in the oxidizable and residual fraction, Cu in the oxidizable fraction, Ni in all four fractions and Zn in the acid soluble/exchangeable and reducible fractions. The pH and heat-drying method affected the fractionation of heavy metals in sludge.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liang
authors.forename: Xun-an
authors.initials: XA
authors.lastname: Ning
authors.forename: Guoxin
authors.initials: G
authors.lastname: Chen
authors.forename: Meiqing
authors.initials: M
authors.lastname: Lin
authors.forename: Jingyong
authors.initials: J
authors.lastname: Liu
authors.forename: Yujie
authors.initials: Y
authors.lastname: Wang
mesh_terms: D005591:Chemical Fractionation; D002681:China; D004396:Coloring Agents / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis*; D010084:Oxidation-Reduction; D012722:Sewage / Q000032:analysis*; D013784:Textiles; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004396:Coloring Agents; D019216:Metals, Heavy; D012722:Sewage; D014874:Water Pollutants, Chemical
keywords: Heavy metals; Principal component analysis; Sequential fraction; Textile dyeing sludge